Archery is a very demanding sport and very sophisticated equipment has been provided for shooting an arrow toward its target. A most critical factor in determining the accuracy of the shot is the force imparted to the arrow upon release of the tensioned bow string. To insure a uniform flight for all of the arrows shot from a bow, various devices have been proposed for measuring the degree of tension produced in the bow string upon pulling it rearwardly to stress the bow, the most common being indicating devices that measure the position of the tip of the arrow relative to the arrow guide rest as each arrow is pulled back when the string is drawn rearwardly. U.S. Pat. Nos. 3,499,414 to Frydenlund; 3,518,959 to Bunker; 3,669,059 to Stuart and 4,061,107 to Smith are examples of known devices for producing an audible signal when the arrowhead reaches the arrow guide rest and the bow string has been retracted a uniform distance for each arrow and is ready for release.
These known clicker devices bear against the side of the arrow at its tip end and provide an audible snap when a spring powered feeler is released. While, of course, the feeler means is designed to move beyond the path of the arrow in its flight, depending upon the construction of the arrow itself, the stabilizing feathers or other portion of the arrow may have a slight but nonetheless deleterious contact with such means located in the direct line of the flight path of the arrow.
Other known devices to produce a signal indicating when the desired tension has been drawn in the string are shown in U.S. Pat. Nos. 3,097,625 to Berquist; 3,867,920 to Westphal and 4,134,383 to Flood. The Berquist teaching makes use of the bending of the bow structure itself to operate a cricket snapper device, Westphal shows an electrical circuit make and break for lighting a signal light and Flood also shows a light indicator located on the bow which the archer must observe either consciously or subconsciously while pulling the string and simultaneously sighting the arrow to effect a proper release.